Explanation:
As a neutral lithium atom contains 3 protons and its elemental charge is given as
. Hence, we will calculate its number of moles as follows.
Moles = 
= 
= 100 mol
According to mole concept, there are
atoms present in 1 mole. So, in 100 mol we will calculate the number of atoms as follows.
No. of atoms = 
=
atoms
Since, it is given that charge on 1 atom is as follows.

= 
Therefore, charge present on
atoms will be calculated as follows.

Thus, we can conclude that a positive charge of
is in 0.7 kg of lithium.
The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T) C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)
The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The A-T pair forms two hydrogen bonds. The C-G pair forms three. The hydrogen bonding between complementary bases holds the two strands of DNA together.
<span>Heavy metals like mercury enter waterways by industrial dumping and poor regulatioin of effluent, and they also enter soil through a similar manner, in which waste is disposed of imporperly. Another source of heavy metals are the gases leaving industry carrying these metals. The metals fall as a solid on to soil and water ways. Therefore, the answer is D.</span>